Snap fit or quick connectors have been found to be useful in a wide range of applications. In particular, they are frequently employed for joining fluid carrying conduits in automotive and industrial applications. Such connectors have found general acceptance as they are typically capable of being closed in a single uni-axial movement which facilitates automated assembly, and entail simple designs which are relatively inexpensive to produce.
A further advantage of quick connect fittings is that they provide an effective seal for handling volatile or hazardous fluids, such as gasoline, while permitting ease of disassembly and reassembly during repair of a host system.
In applications where hazardous material is to flow through a fitting, for example, in vehicle brake lines, prevention of inadvertent release of the quick connector is of primary concern. Accordingly, relatively high axial pull apart strength specifications are mandated. In addition, low insertion forces are required.
Currently, for many high pressure applications, such as with brake lines, threaded fittings are used as connection means. If not aligned correctly, cross threading may result. If excessive torque is applied, over threading may result. As a result of cross-threading or overthreading, the threads are stripped and the material must be scrapped and replaced.
In current anti-lock brake systems, the brake lines are connected to a brake manifold or junction during the assembly process of the vehicle. The threaded connections of the prior art are located close together which increases assembly time and labor as well as the potential for error.
Therefore, it is desirable of the invention to provide a quick connect for high pressure automotive system applications and particularly for brake systems which facilitate assembly of the quick connect so that it is easier and quicker. It is also desirable to provide a quick connector for high pressure fluids that provides high axial pull apart strength and low insertion force specifications. It is further desirable to provide a connector that eliminates the threaded connection to reduce scrap as a result of cross-threading. In addition, it is desirable to provide a connector in a compact package such that the current tube nuts can be replaced with a quick connector so that six brake lines can have connection points on a single brake manifold. It is finally desirable of this invention to provide an improved quick connect having a positive seal around the brake line end, and which provides minimum volumetric displacement, low diametrical clearances and sealing durability.
A further disadvantage typical of prior art high pressure quick connectors is that they must be assembled with an associated tube and shipped to a final destination as a single assembly. Such shipment is expensive and subjects the connectors to damage from mishandling. Such designs frequently require the presence of a resilient seal between the outer peripheral surface of the tube and a mating bore which can result in leakage. This is a particular problem with multi-layer, high pressure steel tube typically used in automotive brake lines. Finally, it is difficult to perform in-process leak checks prior to final installation and very expensive to correct leaks after final installation.